Solubility- a complete and detailed review

For achieving maximum therapeutic effect or action of drug in human body, drug must be bioavailable, which depends on solubility and Pka of drug. The drugs which are poorly water soluble or insoluble produce various side effects such as gastric irritation, stomach pain, peptic and esophageal ulcer etc. A new drug must be soluble as well as permeable to various tissue or organ. Whereas only 9% of new drug candidates have both the characteristics of high solubility and permeability. The solubility behavior of drug is the major challenge for a formulation scientist in the development of new drug. For BCS class II drugs, enhancement of solubility is important parameter before formulation into dosage form. The aim of this review is to improve the solubility, permeability and bioavailability of poorly soluble drugs by using various different techniques.